"well. This complex primitive pattern has, however, been simplified to various degrees in the great majority of vertebrates, as bones have either fused or vanished entirely. In teleosts, only the dentary, articular, and angular bones remain. Cartilagenous fish, such as sharks, do not have any of the bones found in the lower jaw of other vertebrates. Instead, their lower jaw is composed of a cartilagenous structure homologous with the Meckel's cartilage of other groups. This also remains a significant element of the jaw in some primitive bony fish, such as sturgeons. The upper jaw, or maxilla is a fusion of"
"former articular and quadrate bones survive as the malleus and the incus of the middle ear. Finally, the cartilaginous fish, such as sharks, do not have any of the bones found in the lower jaw of other vertebrates. Instead, their lower jaw is composed of a cartilagenous structure homologous with the Meckel's cartilage of other groups. This also remains a significant element of the jaw in some primitive bony fish, such as sturgeons. Mandible The mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human face. It forms the lower jaw and holds the lower"
"a bone called the mandible, more commonly known as the jaw, at their respective alveolar processes. The surface of the oral cavity between the teeth and the inner side of the lips are called the oral vestibule. Surrounding the oral cavity, there are many different muscles that facilitate chewing, opening the mouth, and swallowing. Each muscle, group of muscles, or separate anatomical compartment is encased in a thin fibrous layer of connective tissue called fascia. Normally, the fascia of adjacent structures are in direct contact with each other. However, air or pus can occupy the space between adjacent fascia, known"
"the lower front teeth to the edge of the upper front teeth is 40 millimeters and the overbite is 3 millimeters, then the jaw opening is 43 millimeters. During jaw movements, only the mandible moves. Normal movements of the mandible during function, such as mastication, or chewing, are known as excursions. There are two lateral excursions (left and right) and the forward excursion, known as protrusion. The reversal of protrusion is retrusion. When the mandible is moved into protrusion, the mandibular incisors, or front teeth of the mandible, are moved so that they first come edge to edge with the"
"Angular bone The angular is a large bone in the lower jaw (mandible) of amphibians and reptiles (birds included), which is connected to all other lower jaw bones: the dentary (which is the entire lower jaw in mammals), the splenial, the suprangular, and the articular. It is homologous to the tympanic bone in mammals, due to the incorporation of several jaw bones into the mammalian middle ear early in mammal evolution. In therapsids (mammal ancestors and their kin), the lower jaw is made up of the dentary (the mandible in mammals) and a group of smaller ""postdentary"" bones near the"
"a maxillary process and a mandibular process, giving rise to structures including the bones of the lower two-thirds of the face and the jaw. The maxillary process becomes the maxilla (or upper jaw), and palate while the mandibular process becomes the mandible or lower jaw. This arch also gives rise to the muscles of mastication. Meckel's cartilage forms in the mesoderm of the mandibular process and eventually regresses to form the incus and malleus of the middle ear, the anterior ligament of the malleus and the sphenomandibular ligament. The mandible or lower jaw forms by perichondral ossification using Meckel's cartilage"
"jaw transition is a good classification tool, as most other fossilized features that make a chronological progression from a reptile-like to a mammalian condition follow the progression of the jaw transition. The mandible, or lower jaw, consists of a single, tooth-bearing bone in mammals (the dentary), whereas the lower jaw of modern and prehistoric reptiles consists of a conglomeration of smaller bones (including the dentary, articular, and others). As they evolved in synapsids, these jaw bones were reduced in size and either lost or, in the case of the articular, gradually moved into the ear, forming one of the middle"
"can be determined in the upper jaw, since their sockets are preserved. The connection between the (forehead bone) and (bone running at the upper length of the snout) bones is displaced, and part of the is missing. Most of the snout is preserved, with the of the right side being well-preserved. Only the front part of the left (tooth-bearing bone of the mandible) and some of its broken teeth are preserved. The forelimb (of which all preserved parts are articulated) consists of the middle part of the and (bones of the lower arm), the extremity of the second and third"
"Premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla and usually termed as the incisive bone. Other terms used for this structure include premaxillary bone or os premaxillare, and intermaxillary bone or os intermaxillare. In humans, the premaxilla is referred to as the incisive bone and is the part of the maxilla which bears the incisor teeth, and encompasses the anterior nasal spine and alar region. In the nasal cavity,"
"It forms the lower jaw and holds the lower teeth in place. The mandible articulates with the left and right temporal bones at the temporomandibular joints. Teeth sit in the upper part of the body of the mandible. One fifth of facial injuries involve a mandibular fracture. Mandibular fractures are often accompanied by a 'twin fracture' on the opposite side. There is no universally accepted treatment protocol, as there is no consensus on the choice of techniques in a particular anatomical shape of mandibular fracture clinic. A common treatment involves attachment of metal plates to the fracture to assist in"
"of the lacrimal. This projection then forms the connection of the jawbone with the palatine. At the anterior tip a small grove at the lower edge shows swollen character. Directly above it are two small groves with blunt lumps dividing them. This is representative of a suture and likely the location where the upper jawbone joins the premaxilla in the nasal opening region. The lower jaw measures 15.5mm in length and 1.9mm in width. The edges are elevated to produce a concavity that extends 3.5mm to a point posteriorly. The angular is the largest bone being widest anteriorly. It meets"
"Temporomandibular joint The temporomandibular joints (TMJ) are the two joints connecting the jawbone to the skull. It is a bilateral synovial articulation between the temporal bone of the skull above and the mandible below; it is from these bones that its name is derived. This joint is unique in that it is a bilateral joint that functions as one unit. Since the TMJ is connected to the mandible, the right and left joints must function together and therefore are not independent of each other. The main components are the joint capsule, articular disc, mandibular condyles, articular surface of the temporal"
"The lower jaw has a pair of holes only visible from the inside edge of the jaw. The larger hole at the rear part of the bone complex, known as a posterior Meckelian foramen, was thin and elongated in rhinesuchids. An additional hole on the underside of the jaw joint is only visible from below. This hole, the chorda tympanic foramen, was large in this family. On the upper side of the jaw joint, a thin groove known as an arcadian groove stretches towards the lingual (tongue) side of the jaw and separates other bony bumps located among the jaw"
"where the bones are joined by fibrocartilage, but this articulation fuses together in early childhood. The word ""mandible"" derives from the Latin word ""mandibula"", ""jawbone"" (literally ""one used for chewing""), from ""mandere"" ""to chew"" and ""-bula"" (instrumental suffix). The mandible consists of: The body of the mandible is curved, and the front part gives structure to the chin. It has two surfaces and two borders. From the outside, the mandible is marked in the midline by a faint ridge, indicating the mandibular symphysis, the line of junction of the two pieces of which the bone is composed at an early"
"there is no ""pop"" or ""click"" sound on opening. Temporomandibular joint The temporomandibular joints (TMJ) are the two joints connecting the jawbone to the skull. It is a bilateral synovial articulation between the temporal bone of the skull above and the mandible below; it is from these bones that its name is derived. This joint is unique in that it is a bilateral joint that functions as one unit. Since the TMJ is connected to the mandible, the right and left joints must function together and therefore are not independent of each other. The main components are the joint capsule,"
"the jaw is composed of four bony elements and referred to as a Quadro-articular jaw because the joint is between the articular and quadrate bones. In therapsids (advanced synapsids including mammal ancestors) the jaw is simplified into an articulation between the dentary and the squamous part of the temporal bone, and hence referred to as a dentary-squamosal jaw. In therapsids, the other two bones have moved into the ear to become the malleus and incus. Squamosal bone The squamosal is a bone of the head of higher vertebrates. It is the principal component of the cheek region in the skull,"
"Hyomandibula The hyomandibula, commonly referred to as hyomandibular [bone] (, from , ""upsilon-shaped"" (υ), and Latin: mandibula, ""jawbone"") is a set of bones that is found in the hyoid region in most fishes. It usually plays a role in suspending the jaws and/or operculum (teleostomi only). It is commonly suggested that in tetrapods (land animals), the hyomandibula evolved into the columella (stapes). In jawless fishes a series of gills opened behind the mouth, and these gills became supported by cartilaginous elements. The first set of these elements surrounded the mouth to form the jaw. There are ample evidences that vertebrate"
"specimens examined, except in one juvenile specimen. The mandible (lower jaw) is long and low. The coronoid process, the frontmost of the three main processes (projections) at the back of the jawbone, is large and about as high as the condyloid process behind it. The angular process, below the condyloid, is fairly short and does not extend further backwards than the condyloid. There is no noticeable capsular process (a raising at the back of the jaw that houses the root of the lower incisor). The upper incisors are opisthodont (with the cutting surface oriented backwards) and have orange to yellow"
"the articular process of the lower jaw. Articular bone The articular bone is part of the lower jaw of most vertebrates, including most jawed fish, amphibians, birds and various kinds of reptiles, as well as Stem-mammal. In these animals it is connected to two other lower jaw bones, the suprangular and the angular. It forms the jaw joint by articulating with the quadrate bone of the skull. In mammals, the articular bone has migrated to the middle ear to become the malleus, while the quadrate bone becomes the incus. Paleontologists regard this as a defining characteristic of mammalian fossils. It"
"the periodontium (periodontitis), localized bone tissue is also lost. Alveolar process The alveolar process () (also called the alveolar bone) is the thickened ridge of bone that contains the tooth sockets (dental alveoli) on the jaw bones that hold teeth. In humans, the tooth-bearing bones are the maxilla and the mandible. The curved part of each alveolar process on the jaw is called the alveolar arch. On the maxilla, the alveolar process is a ridge on the inferior surface, and on the mandible it is a ridge on the superior surface. It makes up the thickest part of the maxillae."
"are on located on the upper jaw, and two pairs of mandibular barbels are on the lower jaw. The maxillary barbel has a narrow membrane attached near the base and is straight without any branches. It extends at least as far as the base of the pectoral spine, a bit less than half of length of the head. The outer pair of mandibular barbels extends just past the front of the pectoral girdle, about of the length of the head, and contains three to six weak branches, usually without secondary branches. The inner pair of mandibular barbels is about to"
"jaw growth are most often seen having an anterior open bite, as the mandible is growing away from the maxilla. Whereas those with excessive horizontal growth are seen as having an overbite. Excessive Downward Displacement and Insufficient Downward Displacement: Here on, we will use interchangeably the terms vertical maxillary excess and deficiency with excessive and insufficient downward displacement. In order to understand its manifestations, we need to account for key landmarks such as: · Columella (CM)– The tissue that links the nasal tip to the nasal base, separating the nares. The inferior margin of the nasal septum · Subnasale (SN)"
"and the temporal bone is involved in translational movement—this is the secondary gliding motion of the jaw as it is opened widely. The part of the mandible which mates to the under-surface of the disc is the condyle and the part of the temporal bone which mates to the upper surface of the disk is the articular fossa or glenoid fossa or mandibular fossa. The articular disc is a fibrous extension of the capsule in between the two bones of the joint. The disc functions as articular surfaces against both the temporal bone and the condyles and divides the joint"
"Mandibular canal In human anatomy, the mandibular canal is a canal within the mandible that contains the inferior alveolar nerve, inferior alveolar artery, and inferior alveolar vein. It runs obliquely downward and forward in the ramus, and then horizontally forward in the body, where it is placed under the alveoli and communicates with them by small openings. On arriving at the incisor teeth, it turns back to communicate with the mental foramen, giving off a small canal known as the mandibular incisive canal, which run to the cavities containing the incisor teeth. It carries branches of the inferior alveolar nerve"
"Alveolar process The alveolar process () (also called the alveolar bone) is the thickened ridge of bone that contains the tooth sockets (dental alveoli) on the jaw bones that hold teeth. In humans, the tooth-bearing bones are the maxilla and the mandible. The curved part of each alveolar process on the jaw is called the alveolar arch. On the maxilla, the alveolar process is a ridge on the inferior surface, and on the mandible it is a ridge on the superior surface. It makes up the thickest part of the maxillae. The alveolar process contains a region of compact bone"
"Inferior alveolar nerve The inferior alveolar nerve (sometimes called the inferior dental nerve) is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve. The inferior alveolar nerves supply sensation to the lower teeth. The inferior alveolar nerve is a branch of the mandibular nerve. After branching from the mandibular nerve, the inferior alveolar nerve travels behind the lateral pterygoid muscle. It gives off a branch, the mylohyoid nerve, and then enters the mandibular foramen. While in the mandibular canal within the mandible, it supplies the lower teeth (molars and second premolar) with sensory"
"the lower jaw, the articular, makes a connection with a bone of the cranium called the quadrate bone to form the articular-quadrate jaw joint. In forms transitional to mammals, the jaw joint is composed of a large, lower jaw bone (similar to the dentary found in mammals) that does not connect to the squamosal, but connects to the quadrate with a receding articular bone. Over time, as synapsids became more mammalian and less 'reptilian', they began to develop a secondary palate, separating the mouth and nasal cavity. In early synapsids, a secondary palate began to form on the sides of"
"which the mandibles (lower jaws) of vertebrates evolved. Originally it was the lower of two cartilages which supported the first gill arch (nearest the front) in early fish. Then it grew longer and stronger, and acquired muscles capable of closing the developing jaw. In early fish and in chondrichthyans (cartilaginous fish such as sharks), Meckel's cartilage continued to be the main component of the lower jaw. But in the adult forms of osteichthyans (bony fish) and their descendants (amphibians, reptiles, birds and mammals) the cartilage was covered in bone – although in their embryos the jaw initially develops as the"
"Processes The mandible has two main holes (foramina), found on both its right and left sides: The Inferior alveolar nerve, a branch of the mandibular nerve, (a major division of the trigeminal nerve), enters the mandibular foramen and runs forward in the mandibular canal, supplying sensation to the teeth. At the mental foramen, the nerve divides into two terminal branches: incisive and mental nerves. The incisive nerve runs forward in the mandible and supplies the anterior teeth. The mental nerve exits the mental foramen and supplies sensation to the lower lip. Males generally have squarer, stronger, and larger mandibles than"
"of the mandible. Osteomyelitis of the jaws Osteomyelitis of the jaws is osteomyelitis (which is infection and inflammation of the bone marrow, sometimes abbreviated to OM) which occurs in the bones of the jaws (i.e. maxilla or the mandible). Historically, osteomyelitis of the jaws was a common complication of odontogenic infection (infections of the teeth). Before the antibiotic era, it was frequently a fatal condition. Former and colloquial names include Osteonecrosis of the jaws (ONJ), cavitations, dry or wet socket, and NICO (neuralgia-inducing Cavitational osteonecrosis). The current, more correct, term, osteomyelitis of the jaws, differentiates the condition from the relatively"
"two sides of the mandible. Fibres at the back of the muscle cross the mandible, some being inserted into the bone below the oblique line, others into the skin and subcutaneous tissue of the lower part of the face. Many of these fibers blend with the muscles about the angle and lower part of the mouth. Sometimes fibers can be traced to the zygomaticus, or to the margin of the orbicularis oris. Beneath the platysma, the external jugular vein descends from the angle of the mandible to the clavicle. Variations occur in the extension over the face and over the"
"on pronotum. The size and shape of jaws and antennae varies among individuals. Antennae are dotted and rather long. Their first segment is short and thickened. The third segment is extended and is longer than the fourth and fifth segments combined. The fourth segment is equal or slightly longer than the fifth, and the 11th segment is longer than the first. The lower parts of third to tenth segments have spines. Mandibles are two-toothed and are very large in males, longer than the head; they are much shorter in females. The upper side of the jaw is covered with coarse,"
"nerves form the superior dental plexus above the maxillary teeth. The mandibular (lower) teeth and their associated periodontal ligament are innervated by the inferior alveolar nerve, a branch of the mandibular division. This nerve runs inside the mandible, within the inferior alveolar canal below the mandibular teeth, giving off branches to all the lower teeth (inferior dental plexus). The oral mucosa of the gingiva (gums) on the facial (labial) aspect of the maxillary incisors, canines and premolar teeth is innervated by the superior labial branches of the infraorbital nerve. The posterior superior alveolar nerve supplies the gingiva on the facial"